Antitheft and Alarm Systems: Description and Operation
When triggered, the Anti-theft Protection System honks the horn and flashes the Low Beam Headlamps and Parking Lamps at an intermittent rage of approximately 80 cycles per minute. In addition, the Starting System is disabled until the system is disarmed.
Arming the System
The system is ready to arm any time the Ignition Switch is turned OFF and a door is opened. Voltage to the Anti-theft Module 296 (W/P) wire is removed when the Ignition Switch is turned OFF. Opensing a door closes the Door Ajar Switch in the open door, and a ground path is provided on the 341 (O/W) wire to the Module. This action causes the Module to apply a pulsating ground signal through the 343 (DB/LG) wire to flash the Alarm Indicator lamp.
With the Ignition Switch OFF and a door open, locking the doors with the Power Door Lock Switch or depressing the last two Keyless Entry Buttons begins the arming sequence. Either of these actions applies voltage to the Module on the 117 (PK/BK) wire. The Indicator lamp will now glow steadily.
System arming can be cancelled before all doors are closed by unlocking the door with the Power Door Lock Switch or by using Keyless Entry UNLOCK code. Either of these actions applies voltage to the Module through the 118 (PK/O) wire to cancel arming. The Alarm Indicator will start flashing again. Turning the Ignition Switch to RUN or ACC will also cancel arming by applying voltage to the Module on the 296 (W/P) wire.
The arming cycling is completed by closing all doors. Approximately thirty seconds after the last door is closed, the Indicator Lamp turns off, indicating the arming cycle is complete.
Triggering the System
Opening any door without disarming the system triggers the alarm (lamps and horn) for three minutes, even if the door closes. After three minutes, the lamps and horn will turn off and the Module will return to an armed state. Also, the Starting System is disabled and will remain disabled until the system is disarmed.
Once the system is armed, opening any door causes a ground signal through the 341 (O/W) wire to trigger the alarm circuits in the Module. The Module then provides a pulsating ground signal to the Alarm Indicator through the 343 (DB/LG) wire and to the Horn Relay coil through the 6 (Y/LG) wire. Pulsating battery voltage is applied to the Low Beam Headlamps through the 13 (R/BK) wire and to the Parking Lamp through the 14 (BR) wire.
At the same time, the Module prevents current from energizing the Starter Relay by means of an open circuit between wires 33 (W/PK) and 32 (R/LB) and the car cannot be started.
A Trunk Lock Tamper Switch is also included in the system. If an attempt is made to remove the trunk lock (punch out, etc.), the switch closes and a ground signal is applied to the Module through the 486 (BR/W) wire. This triggers the system in the same manner as previously described for opening a door. The trunk key can be used to open the trunk without triggering the system.
Disarming the System
To disarm the system, a front door can be unlocked with the key, or the Keyless Entry UNLOCK code can be used.
Unlocking a front door with the key provides a ground path through a Door Disarm Switch and the 25 (DG/P) wire to the Module. This ground signal disarms the System.
On models with Keyless Entry, entering the UNLOCK code applies battery voltage through the 163 (R/O) wire to the Module to disarm the system.
If the driver arms the system and remains in the car (all doors closed), the untriggered system can be disarmed by inserting the key in the Ignition Switch and turning the switch to ACC or RUN. The battery voltage applies to the Module on the 296 (W/P) wire disarms the system.